Field of the Invention
The present invention relates to a double-sided tape for a touch screen panel and a manufacturing method, and more particularly to a double-sided tape for a touch screen panel which is located between a panel module and a liquid crystal module of a touch screen, exhibits excellent viscosity while being thin and has excellent shock resistance and an excellent waterproof property, and a manufacturing method.
Description of the Related Art
In portable electronic devices such as an electronic note, a cellular phone, PHS, a camera, a music player and the like, double-sided tapes are being used to fix various members and modules, including an attachment of a protection panel of an information display part and a case. The double-sided tapes have required a lot of useful functions in order to gain competitive advantage in the market, and one of the functions requires giving a waterproof property.
Japanese Laid-Open Patent Publication No. 2005-187531 provides a double-sided tape used to fix parts of an electronic device. For example, there is disclosed a double-sided adhesive sheet which has a maximum value of a loss tangent (tanδ) at a temperature region of −40to −15° C., and has an adhesive layer having side adhesive strength to a specific adhered object of 19N/cm2 or more arranged on double sides of a supporter. The double-sided adhesive sheet comprises a specific adhesive layer to provide excellent adhesion and to exhibit excellent shock resistance which makes it difficult to detach parts due to shock in falling of objects.
However, in attaching rigid bodies as in the attachment of the protection panel and the case, since double-sided adhesive sheet finds difficulty in obtaining complete adhesion between the adhered object and an attachment surface, the parts flooded when there were a few gaps.
Japanese Laid-Open Patent Publication No. 2005-281360 provides a double-sided adhesive tape with excellent adhesion. There is disclosed a double-sided adhesive tape which refers to a foaming body as a base, and has an acrylic-based adhesive layer having a maintenance time of 24 hours or more in a maintenance test at a temperature of −25° C. or less and 0° C., wherein the temperature indicates a maximum value of a loss tangent (tanδ). The double-sided adhesive tape has excellent adhesion to an adhered object, from which members can be very properly connected in the attachment between the members.
However, although the foaming body is used as the base, it is difficult to restrain even a few gaps from occurring on an interface between the member and the adhesive layer. Hence, when a gap or a crack through which water can permeate is present on part of the interface, a permeation path is enlarged therefrom. As a result, it is difficult to implement an excellent waterproof property.
Specifically, portable electronic devices are required to become narrow and thinner according to recent large screens thereof, and as a result, when a narrow tape or a thin tape is required, it is difficult to give a sufficient waterproof property to the tape.